By [1]}, we know that the empirical Rademacher complexity for a function class \(\mathcal {F}_B = \lbrace f(x) = \alpha ^\top \text{ker}_{\theta _f}({\mathbf {X}}^{(j)}, x): \Vert f\Vert _{\mathcal {H}}\le B \rbrace \)  is bounded as
\(\hat{\mathcal {R}}_{S}(\mathcal {F}_B) \le \frac{B\sqrt{\text{tr}[{\mathbb {K}}^{(j)}]}}{n}.\) 
